The present invention relates to an image processing method for determining the optimum image processing conditions of a plurality of images recorded on a photographic film having at least two different photographing formats in accordance with respective photographing formats.
Heretofore, the images recorded on photographic films such as negatives and reversals (hereinafter called as film) have been commonly printed on light-sensitive materials (photographic paper) by means of direct exposure employing an analog photoprinter in which the film image is projected onto the light-sensitive material to achieve its areal exposure.
A new technology has recently been introduced and this is a printer that relies upon digital exposure. Briefly, image information recorded on a film is read photoelectrically, converted to digital data and subjected to various image processing operations; the thus processed digital data of the image information exposes a light-sensitive material digitally. The printer operating on this principle has been commercialized as a digital photoprinter.
In the digital photoprinter, images can be processed as digital image data so that exposure conditions at the time of printing can be determined. Accordingly, the digital photoprinter is capable of performing effective image processing operations such as the correction of washed-out highlights or flat (dull) shadows due to taking of pictures with backlight, an electronic flash or the like, sharpness (sharpening) processing and the correction of color failure, correction of density failure, correction of under- or over-exposure, correction of marginal lumination shortage. Such image processing operations of the digital photoprinter enable to produce high-quality prints that have been impossible to achieve by the conventional analog photoprinter.
In photographing the images (subjects) using an ordinary film of 135 size, a plurality of different photographing formats are provided. They are, for example, a standard size (C type), a high-vision size (H type), a panorama size (P type) and the like. A photographer can decide freely any photographing format at the time of taking pictures whereupon an image is recorded only in a region corresponding to each of photographing formats within respective frames; hence, the image recorded only in the region corresponding to each of the photographing formats can be printed.
As described above, in the film at least two kinds of different photographing formats may be mingled each other in a random manner. Moreover, since information on the photographing format is not recorded on the aforementioned film of 135 size or the like, the photographing format has to date been automatically detected frame by frame and, thereafter, image processing conditions have been calculated based on the thus detected photographing format. Finally, image processing has been performed under the thus calculated image processing conditions to produce finished prints.
However, some cases appear where the photographing formats are wrongly detected or can not be detected at all depending on photographed images. In such cases, that is, detection failures of the photographing format, an operator who is to perform verification looking at a picture (image) represented on a monitor before printing is started enters a command for a correct photographing format as required; the image in a frame of which the photographing format is changed is read again to calculate the image processing conditions all over again.
However, in the above described method, for example, at an apparatus which performs steps below: a plurality of images of either in one unit of a film or in specified number of frames are consecutively read; photographing formats are detected to calculate image processing conditions corresponding to the respective images; the individual images are subjected to the specified image processing conditions in accordance with the thus calculated image processing conditions; and, thereafter, a plurality of processed images are represented on the monitor either as a whole or on a frame basis to verify the processed images, the operator comes to notice the detection failure of the photographing formats only when images are represented on the monitor for verification.
Therefore, when the operator noticed the detection failure of the photographing formats by looking at images represented on the monitor, for example, in a case where the analog photoprinter is used, it is needed to verify the images again in a way that relies on the following steps: a correct photographing format is set; the film is wound off to the frame of the image of which the photographing format was changed; the image is read again after the negative film mask is changed in accordance with the correct photographing format; image processing conditions are calculated; images are subjected to image processing under the calculated image processing conditions; the processed images are represented on the monitor for performing verification again.
Moreover, in another case where the digital photoprinter is used, it is needed to verify the images again in a way that relies on the following steps: a correct photographing format is set; image processing conditions are calculated from the image data in the region corresponding to the changed-over photographing format; the images are subjected to image processing under the thus calculated image processing conditions; and the processed images are represented on the monitor for performing verification again. Accordingly, no matter which printer, the analog photoprinter or the digital photoprinter, the processing is performed twice, which is complicated and time consuming. As a result, efficiency becomes extremely worse.